Legal experts and political pundits are alreading speculating on who President Barack Obama might nominate to the Supreme Court after the death of conservative Justice Antonin Scalia.

The White House, meanwhile, is gearing up for a fight on Capitol Hill: Senate Majority Leader Mitch McConnell said on Facebook that the next president should be responsible for appointing a justice. Obama, however, has pledged to put forward a nominee.

"I plan to fulfill my constitutional responsibilities to nominate a successor in due time," Obama said Saturday. "There will be plenty of time for me to do so, and for the Senate to fulfill its responsibility to give that person a fair hearing and a timely vote. These are responsibilities that I take seriously, as should everyone."

Who will the president pick? Dahlia Lithwick, a senior reporter for Slate, said on MSNBC on Sunday morning that Obama has looked for specific qualities in previous nominations. With Justice Sonia Sotomayor, he wanted empathy; with Justice Elena Kagan, he was looking for uniter. "He doesn't tend to pick bomb-throwers," Lithwick says.

Analysts have floated various possibilities for the nomination, including New Jersey Sen. Cory Booker, Minnesota Sen. Amy Klobuchar and California Attorney General Kamala Harris. Here are a few other names in the mix:

Sri Srinivasan

Many legal observers have said D.C. Circuit Judge Sri Srinivasan, 48, is a likely contender. Jeffrey Toobin, a legal analyst for CNN and a staff writer at The New Yorker, once referred to Srinivasan as a "Supreme Court nominee-in-waiting."

"His credentials would surely appeal to Obama, who has a fondness for technocrats, and his thin paper trail would make him difficult to attack," Toobin wrote in 2013, after Obama nominated Srinivasan to the D.C. Circuit. "Which is why it looks very much like this hearing isn't just a test for Srinivasan — it's a dress rehearsal." (Srinivasan was confirmed by the Senate by a 97-0 vote.)

The judge previously served as the Principal Deputy Solicitor General of the United States, argued more than 20 cases in front of the Supreme Court and was a lecturer for Harvard Law School. He also clerked for former Supreme Court Justice Sandra Day O'Connor. If nominated and confirmed, Srinivasan would be the first Asian-American on the Court.

Watford was appointed by Obama to the Ninth Circuit and confirmed by the Senate in 2012.

"Nine Republicans voted in favor of his nomination. That gives the Administration considerable ammunition to argue publicly that Republicans, by refusing to process the nomination, are blocking someone who is recognized to be qualified," Goldstein wrote. "There is some imperative to move quickly, because each passing week strengthens the intuitive appeal of the Republican argument that it is too close to the election to confirm the nominee."

Watford previously clerked for Supreme Court Justice Ruth Bader Ginsburg, and graduated from the UCLA School of Law. If Watford is nominated and confirmed, he would be the third African-American justice to serve on the Court. It would be the first time two African-American justices served at the same time.

Patricia Millett

Patricia Millett, a judge on the U.S. Court of Appeals for the D.C. Circuit, was also named by several outlets — including The New York Times, Politico and MSNBC's panel Sunday morning — as a potential nominee.

It took almost seven months for her to be confirmed following a Senate debate over the use of filibuster for nominations below the Supreme Court level.

Millett worked on the Appellate Staff of the Civil Division in the U.S. Department of Justice for four years, and as an assistant in the Office of the Solicitor General for 11 years. She has argued more than 30 cases before the Supreme Court, and graduated from Harvard Law School.

Merrick Garland

Chief judge of the U.S. Court of Appeals for the D.C. Circuit Merrick Garland, 63, was considered for previous nominations — and would be more of a "compromise" pick, said Stohr.

"I've been told he's always sort of been held out there as the nominee who might get confirmed in just this situation," Stohr said in an interview on MSNBC on Sunday morning.

"Whether Obama decides to go that direction or not remains to be seen, but he's at least somebody who has a chance because he did have Republican support back in those previous openings. He at least has a chance to be confirmed."

Garland previously served as Principal Associate Deputy Attorney General, as well as Deputy Assistant Attorney General in the Criminal Division of the U.S. Department of Justice. He clerked for Supreme Court Justice William J. Brennan, Jr. and graduated from Harvard Law School.